The present invention generally relates to fasteners insertable into an opening in an article and, more particularly, to a fastener having a body including a base and a flexible elongated portion which is insertable through the opening in the article, with a drive pin of the fastener being movable into operable association with the flexible elongated portion to maintain the fastener in fixed relation relative to the article.
Fasteners are typically utilized to secure two articles together, such as two panels or the like, and include a body and a drive pin. The body of the fastener includes a base and an elongated portion which is insertable through an opening in the article to be secured. The elongated portion of the fastener typically includes flexible arms which extend from the body and define a passage therebetween. After the arms of the elongated portion of the fastener are inserted through the openings in the article to be secured, the drive pin is moved through the passage and between the arms to a driven position wherein the elongated portion of the fastener is expanded and cannot collapse upon itself even if a removal force is applied to the drive pin. As will be appreciated, the expansion of the elongated portion of the fastener opposes removal of the fastener from the holes and thereby secures the panels to each other. Of course, it is desirable to secure the drive pin in a driven position under a relative high retention force.
The drive pins for such fasteners have been known to be predriven into the fastener body and to be frictionally retained therein prior to installation of the fastener into the opening in the article. During shipping and handling of the fasteners, however, the drive pins either become separated from the body of the fastener or inadvertently move to a driven position whereat the drive pin is moved between the flexible arms on the elongated portion of the fastener. As will be appreciated, neither separation of the drive pin from the fastener body nor inadvertent movement of the drive pin to the driven position is acceptable. Moreover, and as will be appreciated by those skilled in the art, low pin insertion forces, such as less than ten pounds, are advantageous for ergonomic reasons. Accordingly, simply increasing the holding force between the drive pin and the body of the fastener to overcome separation therebetween or inadvertent movement of the drive pin is also unacceptable because of the attendant increase in the pin insertion force required to move the pin from the predriven position to a driven position.
Prior art fasteners which require a twisting motion during installation are ergonomically unsound. Moreover, threaded fasteners require expensive and sometimes hazardous installation tools.
Thus, there is a need and continuing desire for a fastener wherein the drive pin is maintained in a predriven position while maintaining a relative low pin insertion force for the drive pin and while concurrently imparting a relative high retention force on the drive pin after the drive pin is moved to a driven position.
In view of the above, and in accordance with the present invention there is provided a fastener including a body and drive or locking pin. The fastener body includes an apertured base and conjoined flexible arms extending from the base and defining a passage therebetween. At a proximal end thereof, the conjoined arms define an outer surface of a predetermined size. The drive or locking pin defines a longitudinal axis and is arranged for movement relative to said body along a predetermined path of travel and within the aperture and the passage defined by the flexible arms. The locking pin has a predriven position and a driven position. In the driven position a lengthwise portion of the pin extends into the passage between the flexible arms to limit movement of the arms inwardly toward the axis of the drive pin. In a preferred embodiment, the drive or locking pin and the body of the fastener are initially formed as a single piece of molded plastic or the like.
A salient feature of the present invention relates to the provision of a resilient lock provided on the fastener body. When the drive pin is in the predriven position, the lock projects into the predetermined path of travel of the pin thereby inhibiting movement of the locking pin toward said driven position. The lock remains in position to inhibit inadvertent linear shifting of the driving pin until the fastener is inserted through an opening in the article with which the fastener is arranged in operable association. In response to the flexible arms of the fastener passing through the opening in the article, the lock is automatically and resiliently deflected from the path of travel of and permits the locking pin to move toward the driven position.
The opening in the fastener body through which the fastener traverses is preferably configured to generally correspond to the cross-section of the drive pin. As such, the drive pin is inhibited from twisting or rotating about its axis and relative to the fastener body as the drive pin is pushed between predriven and driven positions.
In one form, the lock for releasably maintaining the drive pin in a predriven position relative to the fastener body includes a resilient free ended arm connected at one end to the fastener body and extending toward the fastener body base. The drive or locking pin is configured, toward a lower end thereof, with a channel or recess for accommodating the deflected free ended arm to an extent allowing the locking pin to move past the lock and move to the driven position. Preferably, the free end of the lock or arm is configured to promote movement of said locking pin therepast and toward the driven position after the resilient lock is deflected.
In a preferred form, the fastener is configured such that the drive or locking pin is maintained in the driven position with a relatively high retention force. Preferably, the locking pin is provided with a stop linearly spaced from that end of the locking pin inserted into the aperture in the base of the fastener body. Moreover, the resilient arm on the lock is configured with a tab or projection which engages the stop on said locking pin, after the locking pin moves to the driven position, to retain the locking pin in the driven position with a relatively high retention force.
Preferably, the fastener is configured such that the predriven pin is inhibited from being inadvertently or otherwise pulled from the fastener body during shipping or handling of the fastener. In one form, the locking pin includes a predrive retention protrusion extending from the locking pin and engagable with predrive retention structure on the fastener body base to retain the locking pin in the predriven position and to inhibit the predriven locking pin from being inadvertently pulled or otherwise separated from the fastener body during shipping or handling.
Accordingly, a primary object of the present invention is to provide a fastener which is adapted to be arranged in operable combination with an article defining an opening through which at least a portion of said fastener extends, and wherein a relatively low insertion force is required for installation.
Another object of the present invention is to provide a fastener which is adapted to be arranged in operable combination with an article defining an opening through which at least a portion of said fastener extends, and wherein a relatively low insertion force is required to move a drive pin into operable association with an elongated flexible portion of the fastener.
Another object of the present invention is to provide a fastener with high retention forces subsequent to installation.
Yet another object of this invention is to provide a fastener which inhibits inadvertent shifting of a drive pin from a predriven position to a driven position during shipping and handling of the fastener.
Still another object of this invention is to provide a fastener in which a driven pin is retained within the body of the fastener with a relatively high retention force.
A further object of the present invention is provide a fastener in which a predriven pin is inhibited from inadvertently being pulled or otherwise separated from the body of the fastener with a relatively high retention force.
A still further object of the present invention is to provide a fastener which eliminates any twisting or turning movements required for installation.
Another object of the present invention is to provide a fastener which has relatively low manufacturing costs.